Should You Send the Chemoport Tip for Culture?
Yes, you should send the chemotherapy port tip for culture when it is removed for suspected infection, but the material inside the port reservoir is actually more diagnostically valuable than the catheter tip itself.
Optimal Specimen Collection for Subcutaneous Ports
When removing a suspected infected chemotherapy port, the diagnostic approach differs from standard central venous catheters:
Send both the port reservoir contents AND the catheter tip for culture 1. The material inside the port reservoir has higher sensitivity than the catheter tip culture alone for diagnosing catheter-related bloodstream infection (CRBSI) 1, 2.
In a study of 45 ports removed for suspected infection, the reservoir contents were completely predictive of infection, while catheter tip cultures were less accurate even with lower diagnostic thresholds 2. In 7 of 19 confirmed infections, only the reservoir culture was diagnostic 2.
Request quantitative or semiquantitative culture methods (not qualitative broth cultures) for both specimens 1. The diagnostic threshold is >15 CFU by semiquantitative roll-plate method or >100 CFU by quantitative sonication 3.
Pre-Removal Diagnostic Steps
Before removing the port, optimize your diagnostic yield:
Obtain paired blood cultures simultaneously—one from the port hub and one from a peripheral vein—before starting antibiotics 4, 5. This allows for quantitative comparison (≥3-fold higher colony count from catheter) or differential time to positivity (≥2 hours earlier growth from catheter) 1, 4.
Meticulously clean the port hub with alcohol, alcoholic chlorhexidine (>0.5%), or tincture of iodine, allowing adequate drying time (≈30 seconds) before drawing cultures 1, 5. Skipping this step dramatically increases false-positive results 5.
Clearly label each culture bottle to indicate the source (port vs. peripheral) 4, 5.
When to Remove the Port
Remove the chemotherapy port immediately if any of these criteria are met:
- Severe sepsis or hemodynamic instability 4
- Purulence, erythema, or signs of port-pocket infection 1
- Persistent bacteremia/fungemia >72 hours despite appropriate antimicrobial therapy 4
- Infection with S. aureus, P. aeruginosa, fungi, or mycobacteria 4
- Suppurative thrombophlebitis or endocarditis 4
Critical Pitfalls to Avoid
Do not send only the catheter tip—you will miss up to 37% of port infections that are only detectable by culturing the reservoir contents 2.
Do not use qualitative broth cultures—they lack specificity and are not recommended 1, 3.
Do not culture the port routinely upon removal unless infection is specifically suspected, as this increases costs without proven benefit 3.
Do not delay obtaining blood cultures before starting antibiotics—this is the single most important diagnostic step 1, 4, 5.
Interpretation of Results
A definitive CRBSI diagnosis requires:
- Growth of the same organism (species and antibiogram) from both the port specimen (tip or reservoir) AND a peripheral blood culture 3
- OR quantitative criteria met on paired blood cultures (≥3-fold difference or ≥2 hour differential time to positivity) 4, 5
The mortality rate of CRBSI in cancer patients ranges from 12-25%, making accurate diagnosis and appropriate management critical 1.